The European Space Agency is giving the LISA Pathfinder probe what it calls the “Bake, rattle and roll” treatment in the hope it teaches us how to make its successors even better.
As the name suggests, LISA Pathfinder is a test mission for the planned three-vessel LISA space observatory, which will be positioned in a triangular formation 2.5 million kilometres apart so that the craft will be nicely isolated and therefore deliver more reliable results.
All the LISAs look for gravitational waves by “measuring the changing separation of two cubes that are in free-fall” with a Laser Interferometer Space Antenna that gives the program its name. That instrument needs very, very stable conditions in which to work, so by subjecting LISA Pathfinder to heat and movement, the ESA gets the chance to see how its successors will perform if conditions get a bit tricky up there.
Mission boffins will therefore fire the probe's thrusters, conduct thermal tests and run other diagnostics that were only previously performed before it left Earth.
The results of the tests will help the ESA to inform the design of the three future “real” LISA observatories and other missions.
The agency's doing those tests now because LISA Pathfinder's mission is all-but over. After making observations from the L1 point, the craft finished its main mission on June 30th. On July 18th, the ESA will command the probe to shut down.
It's expected the craft poses no risk to anyone, as in April it was placed in an orbit that should keep it clear of the Earth or Moon for a century or more. ®